Dentifrice polishing base



Patented May -19, 1936 2,041,473 nnn'rrmrcs romsnmo BASE Joseph Janota,In, Chicago Heights, 111., assignor to Victor Chemical Works, Chicago,111., a corporation of Illinois No Drawing. Application October 11,1934,

Serial No. 747,983

8 Claims.

This invention relates to improvements in polishing bases fordentifrices, and particularly to polishing bases for powdereddentifrices.

Tricalcium phosphate has heretofore been frequently used as a polishingbase-in the preparation of dentifrices. When used with tooth powderscontaining soap, however, tricalcium phosphate forms a curd uponmoistening unless a relatively high proportion of soap or frothing agentis included. By the use of a large amount of soap it was possible toeffect a partial emulsion of the curd-like precipitate and thus toovercome partially the unsatisfactory effect thereof.

It has now been discovered that the curd may be totally avoided withoutthe use of an excessive amount of soap by including with the tricalciumphosphate a small proportion of an alkali metal pyrophosphate. Forexample, whereas formerly from 6 to per cent. of soap was required, bythe use of a minor proportion of pyrophosphate this may be reduced to 4per cent. or less, while still maintaining excellent emulsifying andfrothing qualities.

A composition embodying the invention comprises a powdered tricalciumphosphate in which has been intimately mixed from 1 to 5 per cent. ofpowdered anhydrous tetrasodium pyrophosphate, and from 1 to 5 per cent.of powdered soap. Flavoring materials such as oil of cloves, oil ofWintergreen and the like may be added, if desired.

A typical dentifrice powder may be made up from 94 parts of tricalciumphosphate, 2 parts of anhydrous tetrasodium pyrophosphate and 4 parts ofsoap. When 2 grams of such a powder is shaken with 50 cc. of water, anexcellent creamylike froth is obtained, and at the same time aconsiderable portion of the tricalcium phosphate remains dispersedthroughout the solution for a considerable length of time after theshaking ceases. A similar powder without the tetrasodium pyrophosphateforms an undesirable flocculent curd-like froth, and the tricalciumphosphate not occluded in the curd-like precipitate settles almostimmediately when shaking ceases. The pyrophosphate has the same efl'ectwhen used in connection with frothing agents of other types. Forinstance, 'sulfonated castor 011 (Turkey red oil) produces a similarcurd-like precipitate in combination with tricalcium phosphate, and

this curd-like precipitate is overcome by the addition of an alkalimetal pyrophosphate.

Calcium carbonate and magnesium carbonate produce a similar curd in thepresence of a frothing agent, and this curd is overcome by the use ofthe alkali metal pyrophosphate, but not quite so satisfactorily as inthe case of the tricalcium phosphate. With the calcium or magnesiumcarbonate a larger quantity of the pyrophosphate, for example, from 5 to10 per cent., is used.

In the absence of soap or frothing agent, no foam is formed in atricalcium phosphate powder, but the addition of the pyrophosphate is anadvantage in that it causes an appreciable dispersion of a portion ofthe tricalcium phosphate.

The term alkali metal as herein used includes sodium potassium andammonium. Either the crystalline or anhydrous phosphates may be used,but in the event that the crystalline material is used the amount isvaried to represent the equivalent of the desired proportion of theanhydrous salt. While as little as 1% of soap and pyrophosphate may beused, it is generally preferred to use from 3 to 4% of soap and from 2to 3% of the pyrophosphate. Higher proportions of alkali metalpyrophosphate may be used without detrimental effect.

The foregoing detailed description has been given for cleamess ofunderstanding only, and no unnecessary limitations should be understoodtherefrom, but the appended claims should be construed as broadly aspermissible, in view of the prior art.

I claim:

l. A dentifrice polishing. base comprising a powder of the classconsisting of tricalcium phosphate and calcium and magnesium carbonateand a minor proportion of an alkali metal pyrophosphate, the amount ofpyrophosphate being markedly less than suflicient to dissolve thecalcium or magnesium present.

2. A dentifrice polishingbase comprising powdered tricalcium phosphateand a minor proportion of an alkali metal pyrophosphate, the amount ofpyrophosphate beingmarkedly less than is required to dissolve thecalcium.

3. A dentifrice polishing base as set forth in claim 2, in which thealkali metal pyrophosphate is tetrasodium pyrophosphate.

4. A base as set forth in claim 2, in which the pyrophosphate is presentin the proportion of 1 to 5 per cent. of tricalcium phosphate.

5. A base as set forth in claim 2, in which the pyrophosphate is 2 to 3per cent. of the tricalcium phosphate.

6. A polishing base as set forth in claim 1, in which the powder iscalcium carbonate.

7. A polishing base as set forth in claim 1, in which the powder ismagnesium carbonate.

8. A base as set forth in claim 1, in which the powder is calciumcarbonate and the pyrophosphate is 5 to 10 per cent. of the calciumcarbonate.

JOSEPH JANOTA, JR.

